now i am no expert. but i did alot of "research" - asking questions on here mostly. but googled it too. We had chickens first. we added peas. I've had no problems. but i did first worm both and give the recommended preventative dose - on side of bottle - of anti biotics also. i was mostly worried about black head from the chickens.
We did not put them together untill the peas were 5 months old. before that the peas had their own pen and we went out every night and put them inside and shut their door when we shut the chickens door.
Now that they're with the chickens they are still separate... they live in the same house - litterally a little one room house a squater used to sleep in long ago. its now divided down the middle with chicken wire. you walk into the chickens area, then you have to open a door to the peas. chickens free range every day. peas free range on the weekends when we're there to watch them. so the peas do walk thru the chickens area and are free to go in it when they're out. i've caught them perching in the chickens area. its ok :) and the chickens always want in the peas area asa the door opens.
all i can say is cleanslyness and prevention have to be a priority. i've got wormer and antibiotics - theres a specific one for black head its long and starts with an M - on hand in case. but all seems well in our bird house.
Oh ya, our peas go in at night just like the chickens :) we started going out at dusk and hearding them in but they go in on their own. there's no catching them. when they start to head that way we follow them. they go in the house and straight to their half and perch. i had really hoped they'd do this. and ya we pushed them to go in since they were baby chicks. i'm glad it works tho :) i hope they always do this. i can't imagine when they're grown up it'll be easy to catch them :)